syzbot


general protection fault in rb_erase_cached

Status: fixed on 2019/03/06 07:43
Subsystems: kernel
[Documentation on labels]
Fix commit: 44039e00171b fou6: Prevent unbounded recursion in GUE error handler
First crash: 1994d, last: 1994d

Sample crash report:
8021q: adding VLAN 0 to HW filter on device batadv0
kasan: CONFIG_KASAN_INLINE enabled
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 7924 Comm: syz-executor928 Not tainted 4.20.0+ #9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:rb_set_parent_color include/linux/rbtree_augmented.h:131 [inline]
RIP: 0010:____rb_erase_color lib/rbtree.c:271 [inline]
RIP: 0010:rb_erase_cached+0x7e2/0x3590 lib/rbtree.c:480
Code: 89 a7 a0 fb ff ff 80 3c 1f 00 0f 85 5a 22 00 00 48 c1 ea 03 48 89 c7 4d 89 66 10 48 c1 ef 03 c6 04 1a f8 4c 89 e2 48 83 ca 01 <80> 3c 1f 00 0f 85 89 22 00 00 48 89 10 4c 89 e2 48 c1 ea 03 80 3c
RSP: 0018:ffff8880914a7090 EFLAGS: 00010082
RAX: 0000000400000001 RBX: dffffc0000000000 RCX: 1ffff11012294e1a
RDX: ffff8880a61222d9 RSI: ffffed1012294e46 RDI: 0000000080000000
RBP: ffff8880914a75f8 R08: ffff8880a61222e0 R09: ffff8880a94642e8
R10: 000000000000005b R11: 0000000000000000 R12: ffff8880a61222d8
R13: ffff8880ae62cef0 R14: ffff8880a94642d8 R15: ffff8880914a75d0
FS:  0000000000000000(0000) GS:ffff8880ae600000(0063) knlGS:0000000009d83840
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000080a78d0 CR3: 00000000952b3000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __dequeue_entity kernel/sched/fair.c:562 [inline]
 set_next_entity+0x2cc/0xb00 kernel/sched/fair.c:4070
 pick_next_task_fair+0xe1b/0x1c20 kernel/sched/fair.c:6980
 pick_next_task kernel/sched/core.c:3318 [inline]
 __schedule+0x4b8/0x1e90 kernel/sched/core.c:3446
 schedule+0xfe/0x350 kernel/sched/core.c:3516
 freezable_schedule include/linux/freezer.h:172 [inline]
 do_nanosleep+0x208/0x750 kernel/time/hrtimer.c:1679
 hrtimer_nanosleep+0x2e4/0x640 kernel/time/hrtimer.c:1733
 __do_compat_sys_nanosleep kernel/time/hrtimer.c:1787 [inline]
 __se_compat_sys_nanosleep kernel/time/hrtimer.c:1774 [inline]
 __ia32_compat_sys_nanosleep+0x1e7/0x280 kernel/time/hrtimer.c:1774
 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
 do_fast_syscall_32+0x333/0xf98 arch/x86/entry/common.c:397
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7fed869
Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000fff9cb8c EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00000000fff9cbb8 RCX: 0000000000000000
RDX: 000000000000004a RSI: 000000000000004a RDI: 00000000fff9cc18
RBP: 00000000fff9cdd8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:

======================================================
WARNING: possible circular locking dependency detected
4.20.0+ #9 Not tainted
------------------------------------------------------
syz-executor928/7924 is trying to acquire lock:
00000000c9165a76 ((console_sem).lock){-...}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136

but task is already holding lock:
00000000d1a32443 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1149 [inline]
00000000d1a32443 (&rq->lock){-.-.}, at: __schedule+0x21e/0x1e90 kernel/sched/core.c:3410

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&rq->lock){-.-.}:
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
       rq_lock kernel/sched/sched.h:1149 [inline]
       task_fork_fair+0xb5/0x7a0 kernel/sched/fair.c:10058
       sched_fork+0x437/0xb90 kernel/sched/core.c:2359
       copy_process+0x1ff6/0x8730 kernel/fork.c:1893
       _do_fork+0x1a9/0x1170 kernel/fork.c:2222
       kernel_thread+0x34/0x40 kernel/fork.c:2281
       rest_init+0x28/0x37b init/main.c:409
       arch_call_rest_init+0xe/0x1b
       start_kernel+0x882/0x8bd init/main.c:741
       x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470
       x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:451
       secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243

-> #1 (&p->pi_lock){-.-.}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152
       try_to_wake_up+0xb9/0x1480 kernel/sched/core.c:1965
       wake_up_process+0x10/0x20 kernel/sched/core.c:2129
       __up.isra.0+0x1c0/0x2a0 kernel/locking/semaphore.c:262
       up+0x13e/0x1c0 kernel/locking/semaphore.c:187
       __up_console_sem+0xb7/0x1c0 kernel/printk/printk.c:236
       console_unlock+0x778/0x11e0 kernel/printk/printk.c:2426
       vprintk_emit+0x370/0x960 kernel/printk/printk.c:1931
       vprintk_default+0x28/0x30 kernel/printk/printk.c:1958
       vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398
       printk+0xba/0xed kernel/printk/printk.c:1991
       check_stack_usage kernel/exit.c:755 [inline]
       do_exit.cold+0x57/0x16a kernel/exit.c:916
       do_group_exit+0x177/0x430 kernel/exit.c:970
       __do_sys_exit_group kernel/exit.c:981 [inline]
       __se_sys_exit_group kernel/exit.c:979 [inline]
       __x64_sys_exit_group+0x44/0x50 kernel/exit.c:979
       do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #0 ((console_sem).lock){-...}:
       lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152
       down_trylock+0x13/0x70 kernel/locking/semaphore.c:136
       __down_trylock_console_sem+0xa8/0x210 kernel/printk/printk.c:219
       console_trylock+0x15/0xa0 kernel/printk/printk.c:2242
       console_trylock_spinning kernel/printk/printk.c:1662 [inline]
       vprintk_emit+0x351/0x960 kernel/printk/printk.c:1930
       vprintk_default+0x28/0x30 kernel/printk/printk.c:1958
       vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398
       printk+0xba/0xed kernel/printk/printk.c:1991
       kasan_die_handler arch/x86/mm/kasan_init_64.c:252 [inline]
       kasan_die_handler.cold+0x11/0x23 arch/x86/mm/kasan_init_64.c:247
       notifier_call_chain+0x179/0x380 kernel/notifier.c:93
       __atomic_notifier_call_chain kernel/notifier.c:183 [inline]
       atomic_notifier_call_chain+0x96/0x190 kernel/notifier.c:193
       notify_die+0x1b2/0x270 kernel/notifier.c:549
       do_general_protection+0x13d/0x300 arch/x86/kernel/traps.c:557
       general_protection+0x1e/0x30 arch/x86/entry/entry_64.S:1142
       rb_set_parent_color include/linux/rbtree_augmented.h:131 [inline]
       ____rb_erase_color lib/rbtree.c:271 [inline]
       rb_erase_cached+0x7e2/0x3590 lib/rbtree.c:480
       __dequeue_entity kernel/sched/fair.c:562 [inline]
       set_next_entity+0x2cc/0xb00 kernel/sched/fair.c:4070
       pick_next_task_fair+0xe1b/0x1c20 kernel/sched/fair.c:6980
       pick_next_task kernel/sched/core.c:3318 [inline]
       __schedule+0x4b8/0x1e90 kernel/sched/core.c:3446
       schedule+0xfe/0x350 kernel/sched/core.c:3516
       freezable_schedule include/linux/freezer.h:172 [inline]
       do_nanosleep+0x208/0x750 kernel/time/hrtimer.c:1679
       hrtimer_nanosleep+0x2e4/0x640 kernel/time/hrtimer.c:1733
       __do_compat_sys_nanosleep kernel/time/hrtimer.c:1787 [inline]
       __se_compat_sys_nanosleep kernel/time/hrtimer.c:1774 [inline]
       __ia32_compat_sys_nanosleep+0x1e7/0x280 kernel/time/hrtimer.c:1774
       do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
       do_fast_syscall_32+0x333/0xf98 arch/x86/entry/common.c:397
       entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

other info that might help us debug this:

Chain exists of:
  (console_sem).lock --> &p->pi_lock --> &rq->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&rq->lock);
                               lock(&p->pi_lock);
                               lock(&rq->lock);
  lock((console_sem).lock);

 *** DEADLOCK ***

2 locks held by syz-executor928/7924:
 #0: 00000000d1a32443 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1149 [inline]
 #0: 00000000d1a32443 (&rq->lock){-.-.}, at: __schedule+0x21e/0x1e90 kernel/sched/core.c:3410
 #1: 00000000ff6af055 (rcu_read_lock){....}, at: atomic_notifier_call_chain+0x0/0x190 kernel/notifier.c:329

stack backtrace:
CPU: 0 PID: 7924 Comm: syz-executor928 Not tainted 4.20.0+ #9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1db/0x2d0 lib/dump_stack.c:113
 print_circular_bug.isra.0.cold+0x1cc/0x28f kernel/locking/lockdep.c:1224
 check_prev_add kernel/locking/lockdep.c:1866 [inline]
 check_prevs_add kernel/locking/lockdep.c:1979 [inline]
 validate_chain kernel/locking/lockdep.c:2350 [inline]
 __lock_acquire+0x3014/0x4a30 kernel/locking/lockdep.c:3338
 lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152
 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136
 __down_trylock_console_sem+0xa8/0x210 kernel/printk/printk.c:219
 console_trylock+0x15/0xa0 kernel/printk/printk.c:2242
 console_trylock_spinning kernel/printk/printk.c:1662 [inline]
 vprintk_emit+0x351/0x960 kernel/printk/printk.c:1930
 vprintk_default+0x28/0x30 kernel/printk/printk.c:1958
 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398
 printk+0xba/0xed kernel/printk/printk.c:1991
 kasan_die_handler arch/x86/mm/kasan_init_64.c:252 [inline]
 kasan_die_handler.cold+0x11/0x23 arch/x86/mm/kasan_init_64.c:247
 notifier_call_chain+0x179/0x380 kernel/notifier.c:93
 __atomic_notifier_call_chain kernel/notifier.c:183 [inline]
 atomic_notifier_call_chain+0x96/0x190 kernel/notifier.c:193
 notify_die+0x1b2/0x270 kernel/notifier.c:549
 do_general_protection+0x13d/0x300 arch/x86/kernel/traps.c:557
 general_protection+0x1e/0x30 arch/x86/entry/entry_64.S:1142
RIP: 0010:rb_set_parent_color include/linux/rbtree_augmented.h:131 [inline]
RIP: 0010:____rb_erase_color lib/rbtree.c:271 [inline]
RIP: 0010:rb_erase_cached+0x7e2/0x3590 lib/rbtree.c:480
Code: 89 a7 a0 fb ff ff 80 3c 1f 00 0f 85 5a 22 00 00 48 c1 ea 03 48 89 c7 4d 89 66 10 48 c1 ef 03 c6 04 1a f8 4c 89 e2 48 83 ca 01 <80> 3c 1f 00 0f 85 89 22 00 00 48 89 10 4c 89 e2 48 c1 ea 03 80 3c
RSP: 0018:ffff8880914a7090 EFLAGS: 00010082
RAX: 0000000400000001 RBX: dffffc0000000000 RCX: 1ffff11012294e1a
RDX: ffff8880a61222d9 RSI: ffffed1012294e46 RDI: 0000000080000000
RBP: ffff8880914a75f8 R08: ffff8880a61222e0 R09: ffff8880a94642e8
R10: 000000000000005b R11: 0000000000000000 R12: ffff8880a61222d8
R13: ffff8880ae62cef0 R14: ffff8880a94642d8 R15: ffff8880914a75d0
 __dequeue_entity kernel/sched/fair.c:562 [inline]
 set_next_entity+0x2cc/0xb00 kernel/sched/fair.c:4070
 pick_next_task_fair+0xe1b/0x1c20 kernel/sched/fair.c:6980
 pick_next_task kernel/sched/core.c:3318 [inline]
 __schedule+0x4b8/0x1e90 kernel/sched/core.c:3446
 schedule+0xfe/0x350 kernel/sched/core.c:3516
 freezable_schedule include/linux/freezer.h:172 [inline]
 do_nanosleep+0x208/0x750 kernel/time/hrtimer.c:1679
 hrtimer_nanosleep+0x2e4/0x640 kernel/time/hrtimer.c:1733
 __do_compat_sys_nanosleep kernel/time/hrtimer.c:1787 [inline]
 __se_compat_sys_nanosleep kernel/time/hrtimer.c:1774 [inline]
 __ia32_compat_sys_nanosleep+0x1e7/0x280 kernel/time/hrtimer.c:1774
 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
 do_fast_syscall_32+0x333/0xf98 arch/x86/entry/common.c:397
Lost 10 message(s)!
---[ end trace 8cfc0b81e87f9ebc ]---
general protection fault: 0000 [#2] PREEMPT SMP KASAN
CPU: 1 PID: 4 Comm:  Tainted: G      D           4.20.0+ #9
RIP: 0010:rb_set_parent_color include/linux/rbtree_augmented.h:131 [inline]
RIP: 0010:____rb_erase_color lib/rbtree.c:271 [inline]
RIP: 0010:rb_erase_cached+0x7e2/0x3590 lib/rbtree.c:480
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Code: 89 a7 a0 fb ff ff 80 3c 1f 00 0f 85 5a 22 00 00 48 c1 ea 03 48 89 c7 4d 89 66 10 48 c1 ef 03 c6 04 1a f8 4c 89 e2 48 83 ca 01 <80> 3c 1f 00 0f 85 89 22 00 00 48 89 10 4c 89 e2 48 c1 ea 03 80 3c
RIP: 0010:lookup_object lib/debugobjects.c:156 [inline]
RIP: 0010:debug_object_deactivate lib/debugobjects.c:542 [inline]
RIP: 0010:debug_object_deactivate+0x16c/0x4b0 lib/debugobjects.c:529
RSP: 0018:ffff8880914a7090 EFLAGS: 00010082
Code: c1 ea 03 42 80 3c 2a 00 0f 85 49 02 00 00 4d 8b 24 24 4d 85 e4 0f 84 d1 00 00 00 49 8d 7c 24 18 83 c3 01 48 89 fa 48 c1 ea 03 <42> 80 3c 2a 00 0f 85 fa 01 00 00 49 3b 4c 24 18 75 c0 49 8d 7c 24
RAX: 0000000400000001 RBX: dffffc0000000000 RCX: 1ffff11012294e1a
RSP: 0018:ffff8880ae707b80 EFLAGS: 00010806
RDX: ffff8880a61222d9 RSI: ffffed1012294e46 RDI: 0000000080000000
RAX: 0000000000000000 RBX: 0000000000000004 RCX: ffff8880ae726620
RBP: ffff8880914a75f8 R08: ffff8880a61222e0 R09: ffff8880a94642e8
RDX: 1f8000000000170c RSI: 0000000000000008 RDI: fc0000000000b860
R10: 000000000000005b R11: 0000000000000000 R12: ffff8880a61222d8
RBP: ffff8880ae707c70 R08: 1ffff11015ce0f5c R09: ffffffff899b1220
R13: ffff8880ae62cef0 R14: ffff8880a94642d8 R15: ffff8880914a75d0
R10: 0000000000000086 R11: 0000000000000003 R12: fc0000000000b848
R13: dffffc0000000000 R14: 1ffff11015ce0f74 R15: ffffffff8b6af3a8
FS:  0000000000000000(0000) GS:ffff8880ae600000(0063) knlGS:0000000009d83840
FS:  0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000080a78d0 CR3: 000000008cd76000 CR4: 00000000001406e0
CR2: 00000000080a78d0 CR3: 00000000952b3000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/01/04 23:30 upstream 96d4f267e40f 0127e3ba .config console log report syz C ci-upstream-kasan-gce-386
* Struck through repros no longer work on HEAD.